A high-voltage installation of this type is described in articles "PD Signal Propagation in GIS Considering Frequencies up to GHz," 8th International Symposium on High Voltage Engineering Yokohama, Japan, pp. 93-96, "A Continuous UHF-Monitor for Gas-insulated Substations," IEEE Transactions on Electrical Insulation Vol. 26, No. 3, June 1991, pp. 469-478, and "Broadband Couplers for UHF Detection of Partial Discharge in Gas-Insulated Substations," IEE Proc.-Sci. Meas. Technol., Vol 142, No. 3, May 1995, p. 237-293.
PCT Patent No. 95/29553 describes a power cable that has a sensor enclosed by the cable sheath. Here various cable characteristics, such as the voltage drop, the temperature, or the pressure, are to be monitored by the sensor.
German Patent No. 31 30 643 describes a conventional coupling arrangement for coupling the carrier frequency message installations to high voltage potential. European Patent No. 0 134 197 describes a probe for the acquisition of partial discharges with a plate-shaped sensor that is insulated from the encapsulating housing, and a slot antenna in the form of an annular gap formed between the plate and the encapsulating housing. On the side of the plate facing away from the interior of the encapsulating installation, a conical member is provided for matching the characteristic impedance to a measurement line.
European Patent No. 0 730 160 describes a similar partial discharge measurement device with a sensor plate that likewise forms an annular slot antenna together with the wall of the encapsulating housing. An element for matching the characteristic impedance is also provided on the side of the plate facing away from the interior of the encapsulating installation.
In conventional devices for transmitting electromagnetic signals, in most cases disk-shaped probes are used as antennas or as capacitive voltage dividers.
Since, for reasons of field formation, such disk-shaped probes must lie as flat as possible on the inner wall of the encapsulating housing, a transceive characteristic results that on the one hand is not sufficiently broadband with regard to the desired frequency range--that is, in the range of the high frequencies only narrow useful bands result--while on the other hand the axis of symmetry of the disk represents the direction of greatest transmission strength or, respectively, reception sensitivity, so that signals propagated laterally, that is, radially in relation to the disk are coupled relatively weakly.